test: Add in_ci utility test function

in_ci checks for environment variables set by a selection of CI systems
and returns true if the test appears to be running in CI. Additionally
it can test for specific CI systems, and returns true if the CI system
is listed.

Deduplicate existing environment checks for Travis and Jenkins.

Signed-off-by: Joe Groocock <me@frebib.net>

test/shell/net.sh

@@ -2,7 +2,7 @@
 
 . "$(dirname "$0")/../util.sh"
 
-if env | grep -q -e '^TRAVIS=true$'; then
+if in_ci travis; then
 	# this often fails in travis with: `address already in use`
 	echo "Travis gives wonky results here, skipping test!"
 	exit

test/shell/t3.sh

@@ -2,7 +2,7 @@
 
 . "$(dirname "$0")/../util.sh"
 
-if env | grep -q -e '^TRAVIS=true$'; then
+if in_ci travis jenkins; then
 	# inotify doesn't seem to work properly on travis
 	echo "Travis and Jenkins give wonky results here, skipping test!"
 	exit

test/shell/yaml-change1.sh

@@ -4,7 +4,7 @@
 
 exit 0	# TODO: this test needs to be update to use deploys instead
 
-#if env | grep -q -e '^TRAVIS=true$'; then
+#if in_ci; then
 #	# inotify doesn't seem to work properly on travis
 #	echo "Travis and Jenkins give wonky results here, skipping test!"
 #	exit

test/test-gotest.sh

@@ -8,7 +8,7 @@ cd "${ROOT}"
 . test/util.sh
 
 # travis is slow for some reason
-if env | grep -q -e '^TRAVIS=true$'; then
+if in_ci travis; then
 	export GO_TEST_TIMEOUT_SCALE=3
 fi
 

test/test-yamlfmt.sh

@@ -13,7 +13,7 @@ ROOT=$(dirname "${BASH_SOURCE}")/..
 cd "${ROOT}"
 . test/util.sh
 
-#if env | grep -q -e '^TRAVIS=true$' -e '^JENKINS_URL=' -e '^BUILD_TAG=jenkins'; then
+#if in_ci travis jenkins; then
 #	echo "Travis and Jenkins give wonky results here, skipping test!"
 #	exit 0
 #fi

test/util.sh

@@ -20,26 +20,43 @@ fi
 
 TIMEOUT="$timeout --kill-after=360s --signal=QUIT 300s"
 
-fail_test()
-{
+in_ci() {
+	if [ $# -eq 0 ]; then
+		test -n "$CI" -o -n "$TRAVIS" -o -n "$JENKINS_URL"
+		return $?
+	fi
+
+	for var in "$@"; do
+		case "$var" in
+		travis)
+			test "$TRAVIS" = "true" && return 0;;
+		jenkins)
+			test -n "$JENKINS_URL" && return 0;;
+		*)
+			continue;;
+		esac
+	done
+	return 1
+}
+
+fail_test() {
 	echo -e "FAIL: $@"
 	exit 1
 }
 
-function run-test()
-{
+function run-test() {
 	"$@" || failures=$( [ -n "$failures" ] && echo "$failures\\n$@" || echo "$@" )
 }
 
 # travis expander helpers from:
 # https://github.com/travis-ci/travis-rubies/blob/build/build.sh
 fold_start() {
-	if env | grep -q -e '^TRAVIS=true$'; then
-		echo -e "travis_fold:start:$1\033[33;1m$2\033[0m"
+	if in_ci travis; then
+		echo -e "travis_fold:start:$1\033[33;1m${@:2}\033[0m"
 	fi
 }
 fold_end() {
-	if env | grep -q -e '^TRAVIS=true$'; then
+	if in_ci travis; then
 		echo -e "\ntravis_fold:end:$1\r"
 	fi
 }